SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '531cabbbfa4c1cc3694f5938492cf3be380a1a5a1d5d454a5d3ebe28a2d8545b' 
  AND token = 'dajTq8gsEIa+/Yth5Cw28BfQFfzgl8HC89fA51ssM+o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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