SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '285933a0b3d52f3c531468dcb0afb0b15898040adf1422ce7157575aafb97022' 
  AND token = 'lcQAjay/ecm5vCtRodmTZdKtf8vdsRY+BgHO5RaPgSE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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