SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c1472e973766d551d0ac01c6676200b38d9c3b348b702224a9252641528f7e31' 
  AND token = 'vZ8E8k8MHTalPBUqPsQ8efP/r6Mbzp+QvRqwggFsXIo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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