SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b229e8ade057c21b0ea26428290328193334ca47dcf2d59a91e90526a7a64940' 
  AND token = 'tYn6NJGX66fpbWgYHLDdyYmuz8//r7kVo7DPf4a7HCA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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