SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'e92b557e279a26bd159d91b35e9c43280ef2d45afdc195ce0cfc590e018d1f04' 
  AND token = 'gc7JKOUa/YsdPlh2HkgOsl5LQ2zpXvXFrkyl4hP03dg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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