SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6a5225620beea1dba2a5c562ea0b2979172025ef3006fe0bfc96e536ba1470e0' 
  AND token = 'wURsCstdCEsdhF9czcvcScO1hmmhpDPUMgVD601Rl+8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00056

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}