SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b5c24202421dcb937945c411a0ee13b6d4276f995413b9dccd79aec9840c831e' 
  AND token = 'VhKL30q1APlKLvcfpjywQrCNxMBUfETemhi71crr8gY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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