SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '56889e622b32dc5fed8097de695b4c22169227bd2f5f3d797d5dba865e351614' 
  AND token = '0vVHck+YcHyv0HSBIRwOUgEI8DsdL7tt/Ue5SZmvqrI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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