SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '823b7e4c581e27729f90891c492bc007f2ccc7029438403e425e2ef0f2fd4c55' 
  AND token = 'lbP60fODjEkyJTeh+Khs1XAhaMmW14+pY3pwqX+dHiU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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