SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5f110eaa74bd39ac0f0e434bd35e8c108b27e7d10853410db35690eb037a2440' 
  AND token = 'vetjmYZ2gYYUIy3CzYhnYZg8XpRas3DBPXuMPbU/50Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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