SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7830fde5e10c4a16afe3f318426c69ce8f4ef576312335f42d4abe844c6b65a9' 
  AND token = 'p4/e3i2nHXvgybO5eV8c3K7FutpUv6nTljBSHXKZ25M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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