SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '7211a6da1f4de5ecc3d2e4876a955537c1c9fd96a09020b1d12e003babc9a6a1' 
  AND token = 'oFGhc6qhE3/JJ5k19w53KUq9MVogG8voOuPcpZ0u0sE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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