SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '91631ff57ac894114669f0ef730c45f723cbacba005d8587dc05732d1890133a' 
  AND token = '2Ahn9NeUN4q8SkUVqPLq+Rg9psY01LDFnQrhrMPTg0M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}