SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '91b05224592e33562d51cadabc631f078e515de142fce5397d576feeacd2cd5e' 
  AND token = 'VTLHbyw1qQwqZ3mjHLOThk1wx08WFEMHaXCL4p6hZhM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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