SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0efc2afb5492bee01e53d97e647d192702531a1da8e70f1354a6342ca4df5a09' 
  AND token = '7Kk/tLhkjaY8kD4ub2wSpVUgkJP0tKjIcKme3Sv9xhE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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