SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '3a0d624553dc7c0186931f723e72a78b6b0a4c59c5237daca097136c2cfd17b8' 
  AND token = 'YHH+kEzvT7uhobosBWroVjLkJ5ilHd3fN2xVWmU+Lu4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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