SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2b11bc808e6f8182fdabc38094d137fe45180211b2fd2f85b234b92b027a6ec8' 
  AND token = 'A6Fmk6EVVMTHpL2fa250a68o5Kw0Ik8IU/njxzLb8YM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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