SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a03564b7de28e9e458e4f8665291f9bc251f5aa075801474501c9e4aacf8904e' 
  AND token = 'hhBE6ytvgKzqeoNYD0eXL9vHtTG1m6bcPEabxRwAAvs=' 
  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"
    }
  }
}