SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f8ac4e7c0f20b775200700d20dfa1cb2c322c2718f80971c0bca3421fd0b7002' 
  AND token = '5et8+WSYKlijw5vfFSJN/hUtJqrdR7/8T3K+cvQC6aM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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