SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f9e60219169c135392d731ca00779721d8d9cabdfa8d53d09c287898347ffd9a' 
  AND token = 'PZT0cthu0Gg9rHonsfXNmMoFJdTwV7Tn44G8x+6lucQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}