SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '74801fd6cd0264f3ff88608676aa8754e63c28a01eae782bc2ec2a2452307b51' 
  AND token = 'VLyRH19NSZUtksLToF9KM/pXUlIRx/xWV8QVqYB8kHY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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