SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '25533f3b76a1cafbf830c320efcc011fb8524964520aa5ed2573f420784cc876' 
  AND token = '2/a4WGHz0ZnPdAmIBewXK5Tp+WiJG6dhz3uiYepRoqs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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