SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aeae637435250d23e4374d4d027800131048de664370c62f301162bf7e1c499b' 
  AND token = 'WXZmYKsEu2R1zbSMrizMM9vP900c7nbaGgGsfR02zGI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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