SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bc8eed8345e9218ede37314562833a757ecf254c7af6fdec407fa29922f12435' 
  AND token = 'ql0H6MqTDwDKqOQG2q6yBEsgdylgR1n89JuD6iIwwHA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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