SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '51157b2c094f767cd092edfe20e491f4b3e0d384dfeebcbb4ec3ab6345819c3b' 
  AND token = 'v+jlHER5QcF2yMKwAYxFujUOHBUMZkJQ97nz0UvwOmY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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