SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a9e41924454fc2b18715828c45d0e6814c80129fbe10457e6cf27794489da8ad' 
  AND token = 'TIQ5XwMHGQxr8NDpSXgc1deuNm1PfAeN1DNxE1cZDzo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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