SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dac55db2ec912698ebfbfe2b980f23c0640192503cd6ddf96a8351cf041b82aa' 
  AND token = 'gefhvHbbMZzkC6kL1swLmojha9fv+9452A5NgpDHyuQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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