SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'f02dd46360e116a0e14740fc069db1672f240098d890406ecb516a7674e480c7' 
  AND token = 'O4rnGujVHa+ZEQ/uJPKCDGzWkWal2dtATxzbEfCKq94=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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