SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '455edadb81ee191081b55537e292e6a2193f0f8ec48498d6ce7cd1319e7e413f' 
  AND token = 'knigZUnDDyLV5hQ0oJZGR/aOZVXbGJIvCWSr7lW1j6w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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