SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '027e7779d766deff080672575bd769632ab35f7cc8b2b58c52630f6f969e2d55' 
  AND token = '+C+H4xjA/3WGZyGt0mJruhiVqe3E2z+wLDPETuwlsgo=' 
  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"
    }
  }
}