SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c95fb3a7ae65db0e1612e05ce5cffe45f327387feb665cf2994678dcc31e5ac7' 
  AND token = 'sFxE6OjWIsIjwFDnUgHu9HMHTjOjeluEv7ZM5+cIdMM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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