SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fc7aaaf2441a2a282e0775ba0a5cd1cb1718bf7afce7ea4b65fdd21e118ec78d' 
  AND token = 'T6xvx03oKDWiLAF/MNpJ0IpuNbfZUOMiPTibvH36vUw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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