SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '623095c1e1e669f6a4527cc76a309e3821c3dd67691bf7fa2c012d443ff6766b' 
  AND token = 'kXwC06dNdsO87hZecv5Qo/eATzULe3s0shjZWnbYCMo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00077

JSON explain

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