SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6a0d54797322c68cb04de19443cc64b7fea92f888f68abf5570cb951c1992cd2' 
  AND token = '5AadipKDEP//rZwBcuZrUuzMmAuUVOQQKTn+/HV5m74=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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