SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '03d4b3bc4f864d42c24d3ee65b0e349864c55883ede8ac4929d1aaa121934705' 
  AND token = 'ocPibTWcnvkflp10jvjxlOJ97hKaKP/xByxKNoFW27k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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