SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4a1b19b7da19766068a33e2327ef105dcfa5644ff4b137b11b28f1bb204a037b' 
  AND token = 'jerObaW6DSynBpOakJEx3q6CG1EFyRE8KxB+ssPDXPQ=' 
  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"
    }
  }
}