SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dea2698646bfe311f2e0600d7ed9dd0ec6316ae61a5e70e268fc62c0a281d024' 
  AND token = 'Cj1QJb+cE4XyV4Crqaz5t5lP/ANz3YnQ3LWyDtEx75o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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