SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ce6193e59b17410b29d2155b06d8f8e39f49c05a5f70d392c230ff238133c4c0' 
  AND token = 'NnwaLJYVtjxDhgpnGM+sZLAj3EYX3nou3UDWKOLeXPE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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