SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7b0b22f147ef27dbd1697bd8fc0fadb8bde9073e378250a27af4fe2490daf915' 
  AND token = 'ijeQgXrLMTFimUh1UNMVa9oSUivqc/ILcProO9XWI+c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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