SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '80a13a4bb6c410e2b8cda3f58123040f84d3a2580f7babffe0f197b12cf6f710' 
  AND token = 'VUFNMyHbrr/rWKjcyVhbqDcnOmB58wK//KiBDguF2WQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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