SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b2c515086e7a8a0d598bc134d19bbb3b9812355d7278f9ae70e143863575bca7' 
  AND token = 'gMgTfsXoJtKW/Uec9aQUI9YqePE9+dS42vYYsiCtIiw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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